I don't think it's a sand sifting star. It's probably some type of asternia star, which some eat corals. I had some that ate my zoas. I got a pair of harlequin shrimp and now I don't have any asternias.
That definitely doesn't look like a sand sifting star to me. I agree with it being an asterina starfish. You can easily pull them off if you want. No need to harpoon them lol.
Don't listen to her!!!! Use a needle and thread and a rubber band and harpoooooooon that SOB oh and don't forget to dress like a pirate and scream "FIRE IN THE HOLE! ". . . If you record it ill give you rep
